This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The purpose of this pilot study is to compare the immunogenicity and safety of the experimental adjuvant rOv-ASP-1 against a negative control (PBS, no adjuvant) as well as a commonly used adjuvant (CpG-C ISS-ODN). Six male rhesus macaques were assigned to this project in April 2010 and placed in one of three experimental groups. All animals were immunized subcutaneously three times with 50ug purified rRBD (receptor binding domain) immunogen plus a control or test adjuvant;Group 1 (n=1) received PBS (no adjuvant), Group 2 (n=2) received 50 ug rOv-ASP-1, Group 3 (n=2) received 100 ug rOv-ASP-1 and Group 4 (n=1) received 250 ug CpG-C ISS-ODN. Blood samples were collected prior to, the day of and seven days after each immunization to measure antibody and cytokine responses. After the third immunization, antibody titers were significantly elevated. Based on these results, the final two immunizations were postponed until the antibody titers diminished. Blood was collected monthly to monitor antibody titers and cytokine responses. Recent results indicate that titers are returning to lower levels and we anticipate immunizing the animals a fourth and last time in March 2011. Blood samples will be collected prior to, the day of and days 7, 30 and 60 post-immunization to measure antibody and cytokine responses. Lymph node biopsies will also be collected 7 and 60 days post-immunization to monitor immune responses. All animals will be released to the TNPRC after the Day 60 post-immunization.